Fendt 8.3.17 – A005 / A014 E-box rear power lift / ECU, OBE: A005, A014 - E-box rear power lift / ECU, OBE — Supply voltage > 18 volt.

The system has detected an overvoltage condition where the supply voltage (Ub 30 circuit) to the rear power lift control module has exceeded 18 volts. To prevent electrical damage, the system automatically triggers a 'Control locked' state, terminating and disabling the electrohydraulic rear power lift control.

• 409 Vario
• 410 Vario
• 411 Vario
• 412 Vario
• 711 Vario
• 712 Vario
• 714 Vario
• 715 Vario
• 716 Vario
• 717 Vario
• 718 Vario
• 916 Vario
• 920 Vario
• 924 Vario
• 926 Vario
• 930 Vario
• 300 Vario Series
• 400 Vario Series
• 700 Vario Series
• 800 Vario Series
• 815 Vario
• 817 Vario
• 818 Vario
• 900 Vario Series
• 933 Vario
• 936 Vario

1. 1

   Measure static battery voltage with the engine off (should be around 12.6V)

2. 2

   Measure alternator output voltage across battery terminals with the engine running (should be 13.5V - 14.5V; >15V indicates a failed voltage regulator)

3. 3

   Inspect the battery for signs of overvoltage damage, such as a sulfur smell, bulging casing, or acid leaks

4. 4

   Verify the CAN bus voltage supply on fuse board A013 (fuses F040, F041) to ensure no fuses blew during the voltage spike

1. 1

   Shut Down

   If the tractor is running and overvoltage is confirmed, shut off the engine immediately to prevent frying the E-box and other sensitive ECUs.

2. 2

   Disconnect Power

   Disconnect the negative battery cable.

3. 3

   Replace the Alternator/Regulator

   Remove the drive belt and unbolt the faulty alternator. Install the replacement unit.

4. 4

   Battery Maintenance

   If the battery was damaged by the overcharging condition (boiled dry or damaged cells), replace the battery. Otherwise, clean the terminals and reconnect.

5. 5

   Clear Fault Codes

   Reconnect the battery, turn the ignition on, and use the FENDIAS diagnostic tool (or the tractor's onboard terminal) to clear the stored 8.3.17 fault code.

6. 6

   Verify Repair

   Start the tractor. Verify with a multimeter that the charging voltage is now stable at ~14V. Test the rear power lift controls to ensure the 'Control locked' state has been lifted and full functionality is restored.